UC-NRLF 


33fl 


DEATH  CAMSS 
Plants  Poisonous  to  Sheep  and  Battle 


By  C.S.  Fleming  &  ff.F.  Peterson 
Univ.  of  Nevada  Bulletin  #101  -  Feb.  19E1 


:  '         Kore&try.  JMaio  L.ibra.r 


THE  UNIVERSITY  QF  NEVADA 
AGRICULTURAL  EXPERIMENT  STATION 


Bulletin  No.  101 


RENO,  NEVADA 


February,  1921 


To  diminish  suffering  and  loss  among  domestic  animals 


DEATH  CAMAS 

(Zygadenus  paniculatus  and  Zygadenus  venenosus) 

Plants  Poisonous  to  Sheep  and  Cattle 


By 

C.  E.  FLEMING  and  N.  F.  PETERSON 
Of  the  Department  of  Range  Management 

Assisted  by 

M.  R.  MILLER 
Of  the  Department  of  Chemistry 

and 

DR.  L.  H.  WRIGHT 
Of  the  Department  of  Veterinary  Science 


PUBLISHED  BY  THE  UNIVERSITY  OF  NEVADA 
RENO,  NEVADA 


I55 


Printed  at  the 

STATE  PRINTING  OFFICE— JOE  FARNSWORTH,  SUPERINTENDENT 
CARSON  CITY,  NEVADA 


NEVADA  AGRICULTURAL  EXPERIMENT  STATION 


BOAED  OF  CONTROL 

Hon.  G.F.TALBOT  (1931)          .        .        . Reno 

Hon.B.  F.  CUBLEB  (1921) Elko 

Hon.  WALTEB  E.  PRATT  (1925) Reno 

Hon.  Mrs.  W.  H.  HOOD  (1927) Reno 

Hon.  MILES  E.NOBTH  (1929) Reno 

OFFICERS 

WALTER  E.  CLARK,  Ph.D President  of  University 

CABOLYN  BECKWITH Secretary 

CHABLES  H.  GORMAN Comptroller 

STAFF 

SAMUEL  B.  DOTEN,  M.A Director  and  Entomologist 

F.  L.  BIXBY,  C.E Irrigation 

(In  cooperation  with  Bureau  of  Public  Roads,  U.  S.  D.  A.) 
GEO.  HABDMAN,  M.S.          .......       Assistant  in  Irrigation 

CHABLES  E.  FLEMING,  B.S.A Range  Management 

EDWARD  RECORDS,V.M.D.  .  Veterinarian 

LYMAN  R.VAWTEB,  D.V.M Pathologist 

MADGE  L.  FINK,  B.A Secretary  to  Veterinary  Department 

M.  R.  MILLER,  B.S Chemist 

MABTHA  RYAN Librarian  and  Secretary  to  Director 


^ 


STUDIES  OF  POISONOUS  RANGE  PLANTS  IN  THE 
UNIVERSITY   OF   NEVADA 


In  undertaking  the  study  of  poisonous  range  plants,  the  Nevada 
Agricultural  Experiment  Station  has  planned  a  series  of  experiments 
to  obtain  information  upon  the  following  points :  ( 1 )  the  part  of  the 
plant  which  is  poisonous,  (2)  the  time  of  the  year  when  it  is  dangerous, 
(3)  the  kinds  of  live  stock  poisoned,  (4)  the  amount  which  must  be 
eaten  in  order  to  cause  illness  or  death,  (5)  the  symptoms  shown  by 
the  poisoned  animals,  (6)  the  conditions  under  which  poisoning  occurs, 
(7)  methods  of  cure  and  treatment,  (8)  and  methods  of  preventing 
poisoning. 

In  addition,  studies  are  made  of  the  post-mortem  conditions  shown 
by  the  poisoned  animal,  and  of  the  chemical  nature  of  the  poisonous 
element  found  in  the  plant. 

The  basis  of  all  these  experiments  consists  of  long  series  of  feeding 
tests  in  which  plants  are  brought  fresh  from  the  ranges  to  the  Univer- 
sity and  are  fed  to  range  animals  in  pens  where  they  are  kept  under 
close  observation. 

This  bulletin  is  a  report  of  the  results  obtained  by  feeding  the  plant 
known  as  death  camas  to  range  sheep  and  cattle. 

S.  B.  DOTEN, 
Director,  Nevada  Agricultural  Experiment  Station. 

UNIVERSITY  OF  NEVADA, 

Reno,  Nevada,  January,  1921. 


48130, 


SECTION    I 

DEATH  CAMAS 

Zygademis  paniculatus  and  Zygadenus  venenosus 
PLANTS  POISONOUS  TO  SHEEP  AND  CATTLE 


SUMMARY 

Death  camas  is  a  common  poisonous  plant  of  the  sheep  and  cattle 
ranges  in  Nevada. 

It  is  a  low-growing  bright-green  plant  related  to  the  lilies  and  the 
onions.  It  comes  up  in  the  very  early  spring  from  a  bulb  buried  eight 
inches  or  more  in  the  ground.  The  bulb  is  much  like  an  onion,  but  it 
has  no  onion  odor,  and  is  covered  with  a  thin  black  coating.  The  leaves 
are  long,  slender,  and  grass-like.  When  the  plants  come  up  they  look 
a  little  like  Indian  corn ;  but  the  leaf  is  narrower  and  more  fleshy,  and 
it  has  a  distinct  ridge  or  keel  on  the  under  side.  At  first  there  appears 
to  be  no  stem ;  but  later  a  flower  stalk  is  sent  up  bearing  a  long  cluster 
of  pale  yellow  flowers. 

The  first  green  shoots  come  up  early  in  the  spring  before  there  is 
grass  on  the  range ;  and  it  is  at  this  season  that  sheep  and  some  cattle 
are  poisoned. 

It  takes  from  one-fourth  to  one-half  pound  of  the  leaves  to  make  a 
range  sheep  sick  when  the  animal  is  confined  in  a  pen ;  it  takes  a  much 
larger  dose,  three  pounds  or  more,  to  kill  a  sheep  under  the  same  condi- 
tions. On  the  range  where  sheep  are  driven  hard  and  have  no  chance 
to  rest  and  recover,  smaller  doses  are  probably  often  fatal. 

On  the  whole,  however,  under  ordinary  range  conditions  it  must  be 
somewhat  difficult  for  even  one  sheep  in  a  band  to  obtain  a  fatal  dose  of 
the  death  camas  leaves;  and  it  is  probable  that  many  losses  thought 
to  have  been  caused  by  death  camas  were  in  reality  caused  by  some 
other  plant. 

Sheep  fatally  poisoned  by  death  camas  froth  at  the  mouth  and 
slobber  freely,  and  occasionally  vomit.  They  grow  weak  in  the  hind- 
legs  and  stagger  when  made  to  walk.  Within  a  few  hours  they  become 
very  dull  and  weak,  standing  with  head  and  ears  drooping  and  the 
back  arched.  Later,  they  go  down  and  thereafter  rise  with  difficulty  if 
at  all ;  becoming  gradually  weaker  and  usually  dying  within  twenty- 
four  hours  from  the  time  of  feeding. 

Cattle  show  much  the  same  set  of  symptoms;  but  are  apt  not  to 
froth  at  the  mouth  and  drool  as  much  as  sheep.  When  in  good  condi- 
tion they  vomit  so  freely  that  they  recover  within  two  or  three  days. 

In  our  experiments  we  did  not  succeed  in  killing  any  young  cattle 
with  death  camas.  Doses  of  three-eighths  of  a  pound  to  two  pounds 
made  the  animal  sick,  but  caused  prompt  and  profuse  vomiting  which 
brought  about  a  fairly  rapid  recovery.  On  the  range,  death  probably 
occurs  only  when  half -starved  cattle  eat  a  considerable  quantity  under 
conditions  where  the  system  is  too  weak  to  throw  off  the  poison  or 
where  weak  animals,  driven  hard,  are  poisoned  and  get  no  chance  to 
rest  and  recpyer. 

There  is  no  known  remedy  for  death  camas  poisoning;  and  even  if 
an  antidote  were  discovered,  it  is  not  likely  that  it  could  be  used  sue- 


r-r--« 


Figure  1.    Toot-Hill  Death  Camas,  the  Entire  Plant,  in  Bloom. 


cessfully  under  range  conditions.  Since  poisoning  occurs  only  when 
weak  and  hungry  animals  are  turned  on  to  death  camas  ranges  where 
there  is  no  grass  or  other  green  feed,  and  since  ordinarily  both  sheep 
and  cattle  will  avoid  death  camas  and  eat  almost  anything  else  in  pref- 
erence, it  is  evident  that  the  way  to  avoid  poisoning  is  to  keep  half- 
starved  animals  off  death  camas  ranges  and  feed  some  hay  until  there  is 
grass ;  and  then  let  the  animals  scatter  out  and  browse  at  will,  choosing 
their  own  forage. 

The  plants  known  as  death  camas  have  long  been  recognized  as 
poisonous,  being  commonly  considered  as  among  the  most  dangerous 
plants  of  our  western  sheep  and  cattle  ranges.  Although  discussed  in 
nearly  all  publications  dealing  with  poisonous  plants,  there  is  little  if 
any  definite  information  concerning  the  quantity  required  to  make  an 
animal  sick  or  to  cause  death;  and  not  much  appears  to  be  known 
about  the  classes  of  live  stock  poisoned,  the  conditions  under  which 
poisoning  is  most  likely  to  occur,  and  methods  of  preventing  losses. 
The  experimental  feedings  and  range  observations  presented  in  this 
bulletin  were  made  for  the  purpose  of  obtaining  exact  information 
upon  these  points. 

Classes  of  Live  Stock  Poisoned. 

All  of  the  range  observations  seem  to  show  that  more  sheep  than 
cattle  or  horses  are  poisoned  by  death  camas.  No  losses  of  horses  have 
been  recorded  by  the  Nevada  Experiment  Station;  and  it  seems  that 
cattle  have  been  poisoned  only  when  hungry  and  in  poor  condition  in 
the  spring  of  the  year.  Many  of  the  losses  on  the  open  range  which 
have  been  attributed  to  death  camas  may  in  reality  have  been  caused 
by  other  plants  not  known  at  the  time  to  be  poisonous.  In  fact,  a  large 
number  of  range  observations  made  by  the  Station  show  that  the 
probability  of  poisoning  by  this  plant  is  by  no  means  so  great  as  is 
commonly  supposed.  This  side  of  the  matter  will  be  discussed  at  length 
farther  on  in  this  bulletin. 

Common  Names. 

Death  camas  is  the  name  by  which  these  plants  are  commonly  known 
on  the  range;  but  they  are  also  called  Mystery  Grass,  Poison  Sego, 
Poison  Onion,  Lobelia,  and  Poison  Camas. 

In  Nevada  the  most  common  kinds  are  the  foot-hill  death  camas 
(Zygadenus  paniculatus) ,  and  the  meadow  death  camas  (Zygadenus 
venenosus).  The  former  grows  in  the  foot-hills  among  sagebrush 
and  other  range  browse ;  the  latter  is  more  plentiful  ,in  moist,  grassy 
places.  The  foot-hill  form  is  more  common  in  Nevada,  being  found  on 
most  of  the  ranges  in  the  northern  part  of  the  State. 

A  Description  of  Death  Camas. 

The  group  of  closely-related  plants  known  as  death  camas  were 
formerly  included  in  the  lily  family ;  but  this  family  has  recently  been 
broken  up  by  botanists  who  have  placed  the  death  camas  in  the 
"bunch-flower  family" (Melanthacece) . 

The  plant  is  erect,  producing  from  two  to  eight  fully  formed  grass- 
like  leaves.  It  springs  from  a  layered  bulb  set  from  two  to  eight 
inches  deep  in  the  soil.  The  bulbs  vary  in  size  according  to  the  age  of 
the  plant ;  but  they  are  commonly  from  one-half  to  one  and  one-fourth 
inches  across  and  are  covered  by  thin,  black,  papery  coats  or  layers. 
The  leaves  are  long,  narrow,  and  curved;  varying  in  length  from  six 


8 


to  eighteen  inches;    they 
they  look  a  good  deal  like 


Figure  2.  Foot-hill  Death 
Camas,  the  Young  Plant 
in  Early  Spring. 


are  usually  less  than  one-half  inch  wide; 

coarse  grass  blades  with  a  projecting  ridge 
like  the  keel  of  a  boat  on  the  under  side. 
They  are  much  thicker  and  more  juicy  than 
ordinary  grass  blades. 

There  is  at  first  no  well-defined  stem,  the 
leaves  appearing  to  rise  from  near  the 
surface  of  the  ground.  The  flowers  are 
greenish  -  yellow  or  whitish,  about  one- 
fourth  inch  across ;  and  are  produced  in  a 
flower  cluster  from  two  to  ten  inches  long. 
The  lower  flowers  bloom  first,  and  may  pro- 
duce seed  pods  before  the  upper  flowers 
bloom.  The  seeds  ripen  in  the  summer; 
but  lie  dormant  until  the  next  spring,  when 
they  sprout  and  grow  into  tiny  leafy 
plants.  These  soon  develop  small  bulbs 
which  may  not  be  any  larger  than  a  pea 
by  the  end  of  their  first  summer's  growth. 
It  takes  a  new  plant  several  seasons  to  form 
a  bulb  sufficiently  large  to  begin  to  produce 
flowers  and  seeds. 

The  foot-hill  death  camas  differs  from 
the  meadow  form  by  having  a  larger  and 
longer  bulb,  lying  deeper  in  the  soil,  usually 
at  a  depth  of  from  five  to  eight  inches ; 
while  the  bulb  of  the  meadow  form  is 
smaller  and  much  shorter  and  is  rarely 
found  more  than  two  inches  deep  in  the 
ground.  The  foot-hill  death  camas  is  also 
a  much  larger  plant;  its  flower  cluster  is 
branched  at  the  base,  while  the  much 
shorter  cluster  of  the  meadow  form  is 
unbranched. 

Plants  Commonly  Mistaken  for  Death  Camas. 

Death  camas  is  most  commonly  confused 
with  the  wild  onion,  although  it  has  no 
onion  odor.  When  in  bloom  the  two  are 
easily  distinguished,  for  all  of  the  flowers 
of  the  onion  cluster  grow  out  from  the  tip 
of  the  flower  stem,  while  the  flowers  of  the 
death  camas  grow  along  the  sides  of  the 
stem  as  in  Figure  4. 

Where  the  Death  Camas  Grows. 

Death  camas  plants  may  be  found  on 
practically  every  stock  range  in  Nevada, 
growing  more  abundantly  in  the  northern 
half  of  the  State  than  in  the  southern. 
The  ground  on  which  the  death  camas 
grows  is  always  quite  moist  in  the  spring 


of  the  year;   and  the  typical  grazing  types  in  which  they  are  found 


are:  (1)  sagebrush,  (2)  grass,  (3)  semimeadow  areas,  and  (4)  typical 
weed  ranges  where  the  vegetation  consists  largely  of  showy  flowering 
plants.  They  do  not  grow  in  the  shade  under  standing  timber.  They 
are  found  on  practically  all  of  the  mountain  foot-hills,  the  high  open 
mountain  park  areas,  and  in  the  sagebrush  country  of  northern  and 
western  Nevada. 

The  Time  of  Year  When  Growth  Begins. 

The  time  when  death  camas  starts  to  grow  in  the  spring  varies  with 
the  season  and  also  with  different  exposures  and  different  soils;  the 
green  shoots  are  sometimes  found  as  early  as  the  middle  of  March. 


Figure  3.     Foot-Hill  Death  Camas.     Plants  in  various  stages  of  growth, 
from  seedlings  to  mature  plant  in  bloom. 

The  plants  make  their  appearance  first  on  sandy  soils  and  on  southern 
exposures.  On  the  dark  loamy  and  clay  soils  their  growth  is  much 
retarded;  probably  because  these  soils  are  moist  and  consequently 
warm  up  less  readily.  If  the  weather  is  fairly  warm  the  death  camas 
will  begin  to  grow  from  ten  days  to  two  weeks  after  the  snow  melts 
out  in  the  spring;  and  the  leaves  are  soon  high  enough  to  cause  loss. 
By  the  latter  part  of  June  on  the  lower  ranges,  the  plant  has  usually 
died  down. 

How  the  Flavor  of  Death  Camas  Affects  the  Probability  of  Poisoning. 

All  species  of  death  camas  which  grow  in  Nevada  have  a  bitter  flavor 
and  are  extremely  distasteful  to  cattle  and  sheep.    In  all  our  feeding 


10  

tests  it  was  practically  impossible  to  get  either  sheep  or  cattle  to  eat 
this  plant  readily,  even  after  going  hungry  for  two  or  three  days. 
When  a  hungry  animal  was  first  fed,  a  few  mouthfuls  would  be  eaten ; 
but  almost  as  soon  as  the  plant  juices  came  in  contact  with  the  mouth 
the  animal  would  begin  to  wrinkle  its  nose  and  move  its  tongue  in  such 
a  manner  as  quickly  to  get  rid  of  what  was  in  its  mouth. 

In  order  to  get  any  large  number  of  plants  into  an  animal  it  was 
necessary  to  resort  to  forced  feedings,  which  consisted  mainly  in  plac- 
ing the  ground  leaves  so  far  back  in  the  animal's  mouth  that  it  had 
to  swallow  what  was  given  it.  When  this  plant,  mixed  with  palatable 


Figure  4.  Foot-Hill  Death  Camas  (on  left)  and  Wild  Onion.  Notice  the  differ- 
ence in  the  arrangement  of  the  flowers  on  the  stem.  The  flowers  of  death 
camas  are  scattered  along  the  sides  of  the  stem;  those  of  wild  onion  form 
a  round  cluster  at  the  end  of  the  stem. 

weeds  and  grasses,  was  fed  to  hungry  animals  they  would  sort  out  the 
grasses  and  weeds  and  eat  them,  avoiding  the  death  camas  wherever 
possible.  This  shows  clearly  how  sheep  and  cattle  dislike  this  poisonous 
plant  and  try  to  avoid  eating  it. 

On  many  of  the  grazing  ranges  in  the  western  part  of  Nevada,  sheep 
have  been  closely  observed  while  grazing  on  ground  supporting  death 
camas,  with  weeds,  browse,  and  a  scattering  stand  of  grasses.  The 
sheep  nibbled  weeds  and  grasses  all  around  the  death  camas,  leaving  it 
almost  untouched.  Naturally,  no  losses  occurred  under  these  conditions. 


11 


On  several  of  these  ranges  it  was  noticed  that  the  death  camas  plants 
had  been  grazed  by  some  animal.  A  study  of  conditions  on  near-by 
ranges,  where  it  was  known  that  there  had  been  no  live  stock  that 
season,  revealed  the  fact  that  a  number  of  rodents,  common  ground 
squirrels  among  others,  were  eating  the  leaves  and  digging  up  the 
bulbs.  Ordinarily,  if  there  had  been  sheep  on  these  ranges  and  poison- 
ing had  occurred,  it  would  have  been  seen  that  the  death  camas  plants 
had  been  grazed ;  and  they  would  have  been  blamed  for  the  losses. 

A  series  of  similar  observations  were  made  on  Peavine  Mountain, 
near  Reno  by  J.  A.  Longyear  who  states  that  the  tops  of  death  camas 
plants  are  nibbled  rather  freely  by  ground  squirrels. 

Because  of  the  fact  that  in  the  experimental  work  it  took  a  large 
quantity  of  death  camas  to  kill  a  sheep,  a  series  of  feeding  tests  were 
made  with  the  most  palatable  young  green  weeds  and  grasses  to  find 
out  the  amount  of  such  plants  a  range  sheep  will  eat  before  its  hunger 
is  satisfied. 

Two  yearling  lambs  in  medium  condition  were  fed  a  mixture  of  green 


Figure  5.    Foot-Hill   Death   Camas. 
Plants  beginning  growth  in   early 
spring. 


Figure  6.  The  Foot- 
Hill  Death  Camas. 
This  plant  has 
been  nibbled  by 
ground  squirrels. 


grasses  and  weeds.  These  animals  were  fed  during  a  series  of  days  all 
they  would  eat  in  the  forenoon  and  afternoon.  The  average  consump- 
tion of  weeds  and  grass  was  four  and  one-half  pounds  on  each  half- 
day,  or  nine  pounds  per  day. 

Two  old  ewes  weighing  80  and  90  pounds  respectively  were  put  to 
the  same  test  as  the  lambs ;  and  it  was  found  that  on  the  average  each 
would  eat  a  little  over  eight  pounds  daily.  These  tests  probably  show 
quite  accurately  the  quantity  of  green  feed  eaten  by  a  range  sheep  in  a 
single  day. 

With  death  camas  the  experimental  feeding  tests  showed  that  the 
smallest  amount  which  will  make  a  sheep  sick  is  between  one-fourth 
pound  and  one  pound.  Amounts  of  one-fourth  to  two  and  one-half 
pounds  in  each  feeding  made  the  sheep  sick ;  but  none  died  from  the 
direct  effects  of  the  poisoning.  However,  two  were  so  weakened  that 
they  died  later;  one  from  inflammation  and  ulceration  of  the  fourth 


12  

stomach,  the  other  from  pneumonia.  Quantities  of  three  pounds  or 
more  killed  the  animals  in  all  cases,  with  the  exception  of  a  single  sheep 
which  appeared  far  more  resistant  to  poisoning  than  the  average 
animal. 

When  we  compare  the  capacity  of  a  sheep 's  stomach,  approximately 
four  and  one-half  of  green  grass  and  weeds  at  a  single  feeding,  with  the 
quantity  of  death  camas  required  to  kill,  approximately  three  pounds 
or  more ;  then  it  would  appear  that  the  sheep  would  have  to  graze  very 
largely  on  death  camas  in  order  to  secure  a  fatal  dose. 

In  order  to  get  a  clear  idea  of  how  thick  a  stand  of  death  camas  there 
is  on  the  range  early  in  the  spring  when  the  danger  is  greatest,  square- 
rod  plots  were  laid  out  where  death  camas  (Zygadenus  paniculatus] 
appeared  most  abundant  on  the  foot-hills  southwest  of  Reno.  On 
April  12,  1918,  32  plants,  all  that  grew  on  one  square  rod,  were  cut  off 
at  a  height  of  three-quarters  inch  above  the  ground.  The  total  weight 


Figure  7.     Foot-Hill  Death  Camas.     The  leaves  appear  to  spring  directly 
from  the  ground  without  any  stem. 

was  32.8  grams,  or  a  little  more  than  an  ounce.  On  April  15,  52  plants 
were  cut  from  two  square  rods  and  the  total  weight  of  leaves  cut  was 
28.6  grams  per  square  rod,  or  approximately  one  ounce.  At  this  rate 
it  would  take  sixteen  square  rods  to  produce  a  single  pound  of  the 
plant.  The  leaves  at  this  time  were  from  four  to  eight  inches  high. 

On  all  of  these  plots  there  was  a  far  heavier  stand  of  death  camas 
than  would  ordinarily  be  found  on  any  of  the  ranges  in  Nevada.  If 
the  plants  really  grew  as  thickly  on  the  range  as  on  these  selected  plots, 
and  if  they  had  reached  a  height  of  from  four  to  eight  inches,  then  each 
acre  would  produce  from  10  to  12  pounds  of  death  camas,  enough  to 
poison  fatally  some  three  or  four  sheep.  The  death  camas  was  cut  and 
weighed  at  a  time  of  year  when  all  other  green  vegetation  was  very 
scarce,  and  the  likelihood  of  poisoning  was  greatest. 

On  May  17,  1918,  when  other  range  vegetation  was  quite  abundant, 


13  

17  death  camas  plants,  all  that  grew  on  a  square  rod,  were  clipped 
three-fourths  of  an  inch  from  the  surface  of  the  ground ;  they  weighed 
4.8  ounces,  somewhat  more  than  one-fourth  pound.  The  plants  were 
then  in  full  bloom,  some  of  them  going  to  seed.  At  this  rate  and  at  this 
time  of  year  an  acre  would  produce  approximately  48  pounds  of  death 
camas,  enough  to  poison  fatally  about  16  head  of  sheep.  However,  the 
plant  does  not  grow  as  thickly  as  this  uniformly  over  any  sheep  range. 
The  square-rod  plots  were  selected  areas,  chosen  because  they  supported 
an  unusual  number  of  plants. 

Foot-Hill  Death  Camas  (Zygadenus  paniculatus)  Feeding  Experiments  with  Sheep. 

In  the  course  of  the  years  1918  and  1919,  69  feedings  were  made  to 
sheep.  Most  of  these  feedings  were  of  leaves,  only  a  few  feedings  being 
made  of  the  flower-heads,  seed-heads,  and  bulbs.  The  results  of  these 
feedings  are  condensed  in  Table  I. 

The  results  of  the  experiments  presented  in  this  table  may  be 
summarized  as  follows : 

(1)  None  of  the  nine  feedings  of  -J  pound  each  had  any  appreciable 
effect  upon  the  animal,  indicating  that  this  quantity  of  the  plant  is 
practically  harmless ;  (2)  out  of  the  16  feedings  of  J  pound  of  the  tops, 
six  tests  produced  no  visible  symptoms,  while  10  made  the  animals 
appreciably  sick.  These  feedings  show  that  if  sheep  in  a  range  flock 
eat  as  little  death  camas  as  \  pound  each,  trouble  may  possibly  follow. 

A  single  feeding  of  \  pound  of  the  bulbs  made  one  sheep  sick,  but  in 
a  few  hours  it  had  completely  recovered.  It  takes  several  plants  to 
make  \  pound  of  the  bulbs,  more  plants  in  fact  than  a  sheep  could 
possibly  ever  pull  up  ;  so  the  bulbs  as.  a  poisonous  part  of  the  plant  may 
be  completely  disregarded. 

(3)  Nine  out  of  12  feedings  of  \  pound  of  the  tops  produced  typical 
symptoms  of  poisoning,  while  three  apparently  had  little  effect  upon 
the  animals.     A  half-pound  of  the  tops  will  generally  make  a  sheep 
sick ;  any  larger  quantity  will  almost  always  cause  severe  poisoning. 

(4)  Four  out  of  five  feedings  of  f  pound  each  made  the  animals 
sick.    These  sheep  were  much  more  seriously  affected  than  those  fed  \ 
pound  each. 

(5)  Of  seven  feedings  of  one  pound  each,  six  caused  severe  poisoning 
while  one  had  no  effect.     Apparently  one  pound  is  as  much  as  any 
sheep  can  eat  without  danger  of  serious  poisoning. 

(6)  Four  feedings  of  from  \\  to  1J  pounds  all  caused  severe  but  not 
fatal  poisoning. 

(7)  Five  feedings  of  quantities  varying  between  If  pounds  and  2£ 
pounds  caused  very  severe  poisoning,  resulting  in  death  in  two  cases. 

(8)  All  feedings  of  three  pounds  each  resulted  fatally.     However, 
sheep  No.  18  was  twice  fed  3^  pounds  without  a  fatal  result,  although 
the  animal  was  severely  poisoned  and  was  sick  for  more  than  a  day  each 
time.    This  animal  appeared  to  be  very  resistant  to  poisoning  by  death 
camas ;  later,  in  tests  with  other  plants,  she  showed  the  same  resistance 
to  poisoning. 

(9)  Three  feedings  of  four  pounds  of  the  tops  all  caused  death.    It 
seems  fair  to  assume  that  under  ordinary  conditions  no  sheep  can  eat 
such  a  quantity  of  death  camas  and  live.    Still,  four  pounds  is  a  far 
greater  quantity  than  any  sheep  is  likely  ever  to  find  on  the  range. 

(10)  Of  three  feedings  of  quantities  of  seed-heads  varying  between 


14 


TABLE  I 

FOOT-HILL  DEATH  CAMAS  (Z.  paniculatus) .    THE  FRESH  GREEN  PLANT 

FED  TO  SHEEP. 


Animal 
No. 

wjgjht    Date  fed 

Time  fed 

Amount 
fed,  Ibs. 

Time  symptoms 
appeared 

Time  of  death 
or  recovery 

Final  result 

13 

69 

72 
65 
67 
64 
70 
56 
81 
79 
93 
90 
96 
83 
71 
61 
82 
93 
93 
93 
93 
116 
75 
72 
73 
83 
77 
72 
56 
56 
53 
72 
120 
75 
75 
69 
68 
70 
66 
66 
75 
64 
64 
82 
94 
63 
70 
80 
75 
67 
68 
73 
72 
70 
65 
68 
75 
83 
77 
94 
94 
73 
83 
96 
67 
65 
12 
93 
88 
81 

5-22-18 
5-22-18 
5-22-18 
5-22-18 
6-  4-18 
6-  4-18 
6-  4-18 
5-  6-18 
5-  6-18 
5-  9-18 
5-10-18 
5-10-18 
5-14-18 
5-22-18 
5-22-18 
5-22-18 
5-22-18 
5-24-18 
5-25-18 
6-  4-18 
6-  4-18 
4-17-19 
5-  6-18 
5-  6-18 
5-  9-18 
5-14-18 
5-15-18 
5-22-18 
5-24-18 
5-25-18 
5-25-18 
6-  4-18 
4-17-19 
4-23-19 
5-  5-19 
5-  7-18 
5-22-18 
5-23-18 
5-24-18 
4-18-19 
5-24-18 
5-25-18 
5-  9-18 
5-10-18 
5-22-18 
4-22-19 
4-23-19 
5-  9-18 
5-14-18 
5-  9-18 
5-10-18 
5-10-18 
5-14-18 
5-24-18 
5-16-18 
5-22-18 
5-15-18 
5-22-18 
5-18-18 
5-24-18 
5-17-18 
5-17-18 
5-22-18 
5-  6-18 
6-  4-18 
6-  4-18 
5-27-18 
5-15-19 
5-  5-19 

2:15  p.  m. 
2:20  p.  m. 
2:25  p.  m. 
2:30  p.  m. 
2:15  p.m. 
2:25  p.  m. 
2:30  p.  m. 
11:10  a.  m. 
11:30  a.m. 
10:20  a.  m. 
9:30  a.  m. 
9:40  a.  m. 
11:10  a.  m. 
2:35  p.m. 
2:40  p.  m. 
2:50  p.  m. 
2:55  p.  m. 
9:10  a.  m. 
10:20  a.  m. 
2:35  p.  m. 
2:40  p.  m. 
11:45  a.  m. 
11:00  a.  m. 
2:40  p.  m. 
11:45  a.  m. 
11:20  a.  m. 
10:40  a.  m. 
3:15  p.m. 
9:20  a.  m. 
10:30  a.  m. 
10:40  a.  m. 
2:50  p.  m. 
11:45  a.  m. 
11:00  a.  m. 
10:00  a.  m. 
11:30  a.  m. 
3:40  p.m. 
10:35  a.  m. 
9:25  a.  m. 
9:30  a.  m. 
9:30  a.  m. 
10:40  a.  m. 
11:35  a.  m. 
11:05  a.  m. 
3:50  p.m. 
10:00  a.  m. 
10:30  a.  m. 
11:50  a.  m. 
10:40  a.  m. 
10:40  a.  m. 
11:35  a.  m. 
10:35  a.  m. 
10:15  a.  m. 
9:40  a.  m. 
10:15  a.  m. 
10:15  a.  m. 
10:00  a.  m. 
11:20  a.  m. 
10:35  a.  m. 
10:25  a.  m. 
10:15  a.  m. 
10:30  a.  m. 
10:40  a.  m. 
2:55  p.  m. 
2:19  p.  m. 
2:20  p.  m. 
10:30  a.  m. 
9:40  a.  m. 
9:50  a.  m. 

j 

: 
: 

1 

1 
1 

2 
2 
2 
2 
3 
3 
3 
3 
4 
4 
4 

; 
: 

S 

! 

t 

i 

'„ 

Negative 

8 

Negative 

6  

Negative 

24 

Negative 

28 

Negative 

27 

Negative 

26 

Negative 

25. 

2:55  p.m. 
3:30  p.m. 
2:30  p.  m. 
3:30  p.  m. 

5:00  p.  m. 
5:00  p.  m. 
5:00  p.  m. 
4:30  p.  m. 

Recovery 
Recovery 
Recovery 
Recovery 

Negative 

23--. 

25  
25 

21  
9 

Negative 

7  

17 

7:00  p.  m. 
8:00  p.  m. 
3:55  p.  m. 
3:55  p.  m. 

5-23—10:00  a.  m. 
5-23—  3:00  p.  m. 
5-23—10:00  a.  m. 
7:00  p.  m. 

Recovery 
Recovery 

10— 

Recovery 
Recovery 

25 

25 

Negative 

25     

12:00  m. 
3:50  p.  m. 

3:00  p.  m. 
7:45  p.  m. 

Recovery 
Recoverv 

25 

14 

Negative 

26 

Negative 

8 

Negative 

20 

Negative 

9  

6:40  p.  m. 
2:30  p.m. 
1:00  p.m. 
4:55  p.  m. 
10:50  a.  m. 
2:40  p.  m. 
1:40  p.m. 
4:50  p.m. 

5-10—  8:00  a.  m. 
5:00  p.  m. 
5:00  p.  m. 
10:00  p.  m. 
11:50  a.  m. 
8:00  p.  m. 
3:00  p.m. 
7:45  p.  m. 

Recovery 
Recovery 
Recovery 
-._    Recovery 
Recovery 
Recovery 
Recovery 

5 

8 

26  
26 

26  

16 

2... 

Recovery 
Negative 

29 

26 

Negative 

46  - 

4:45  p.  m. 

7:00  p.  m. 

Recovery 
Negative 

11 

27    

7:00  p.m. 
1:40  p.  m. 
2:15  p.m. 
1:30  p.  m. 
2:15  p.m. 
12:00  m. 
1:20  p.m. 
3:30  p.  m. 
7:00  p.  m. 
2:40  p.  m. 

5-23—  8:00  a.  m. 
8:00  p.  m. 
4:15  p.  m. 
5:00  p.  m. 
4:05  p.  m. 
8:00  p.  m. 
9-11—  8:00  a.  m. 
5:00  p.  m. 
5-23—  8:00  a.  m. 
4-23—  8:00  a.  m. 

Recovery 
Recovery 

27 

27  

Recovery 
Recovery 
Recovery 
Recovery 
Recovery 
Recovery 
Recovery 

29 

28.  __ 

28 

10... 

18 

28 

46  

Recovery 
Negative 

29 

12  

2:30  p.  m. 
3:30  p.  m. 
1:20  p.m. 
3:15  p.m. 
2:30  p.  m. 
2:30  p.  m. 
11:05  a.  m. 
2:30  p.m. 
12:30  p.  m. 
1:00  p.  m. 
12:30  p.  m. 
1:00  p.  m. 
10:00  a.  m. 
11:20  a.  m. 
11:20  a.  m. 
12:20  p.  m. 
11:00  p.m. 

4:30  p.  m. 
5:00  p.  m. 
6:40  p.  m. 
5:15  p.  m. 
5-11—  8:00  a.m. 
5-15—  8:00  a.  m. 
2:00  p.m. 
5-18—  8:00  a.  m. 
5-26—11:00  a.  m. 
5-18—  9:00  a.  m. 
5-23—  1:00  a.  m. 
5-19—  8:00  a.  m. 
5-25—  2:00  p.  m. 
5-18—  1:00  p.m. 
5-18—  8:00  a.  m. 
1:25  p.  m. 
5-  7—  6:00  p.  m. 

Recovery 
Recovery 
Recovery 
Recovery 
Death 

24 

19  

20    . 

3 

16  

...    Recovery 
Recovery 

29 

19  
12  
22.  _. 
5  
18  
18  
20  
9  
21  
24  
29  
8  
25  
29  
26  

Recovery 
Death 

Death 

Death 

Recovery 
Recovery- 
Death 

Death 

Death 

—  'Recovery 
t  Negative 

tNegative 

11:30  a.  m. 

5-~2~8~—  sVob  a.  m. 

—  tRecovery 
tNegative 

4:45  p.m.                      7:00  p.m. 

_-.  ^Recovery 

*Flower  heads  fed.     tSeed  heads  fed.    JBulbs  fed. 


15 

•J  and  Vio  of  a  pound,  one  caused  sickness  and  two  were  without  result. 
Apparently  the  green  seed-heads  are  about  as  poisonous  as  the  leaves 
and  stems.  The  number  of  tests,  however,  was  not  great  enough  to 
prove  this  conclusively.  As  a  cause  of  poisoning  in  range  sheep 
it  is  believed  that  the  seed-heads  of  death  camas  are  of  very  little 
importance. 

Symptoms  of  Poisoning  in  Sheep  by  Foot-Hill  Death  Camas. 

Small  doses,  from  J  to  f  of  a  pound,  cause  salivation  or  slobbering  in 
nearly  every  case.  A  few  cases  show  nausea  and  vomiting;  there  is 
often  a  marked  increase  in  the  rate  of  respiration  sometimes  amounting 
to  panting.  The  breathing  is  very  irregular;  for  a  time  it'  is  rapid, 
then  very  slow.  In  some  cases  there  is  a  muscular  weakness,  which  is 
most  noticeable  in  the  hind-legs. 

With  larger  doses,  from  one  to  two  pounds,  there  is  in  addition  to 
the  above  symptoms  a  period  of  dullness  during  which  the  animal 
stands  with  the  back  arched  and  the  head  and  ears  drooping.  With 
still  larger  doses  the  animal  becomes  so  weak  as  to  be  unable  to  rise. 

In  some  cases  the  mucous  membrane  of  mouth  and  tongue  appeared 
blue ;  and  two  sheep  showed  such  a  spasmodic  twitching  of  the  muscles 
as  occurs  in  strychnine  poisoning. 

Time  Necessary  for  Symptoms  of  Poisoning  to  Appear. 

The  time  which  elapsed  from  the  time  of  feeding  until  symptoms 
appeared  varied  from  one  to  seven  hours,  the  average  being  three  hours 
and  ten  minutes.  The  time  was  slightly  less  for  the  larger  doses.  With 
doses  of  less  than  two  pounds  the  time  averaged  three  hours,  twenty-two 
minutes ;  with  doses  of  three  pounds  or  more  the  average  was  two  hours, 
twenty-five  minutes. 

Length  of  Time  the  Poisoned  Sheep  Were  Sick. 

The  length  of  time  through  which  the  sheep  remained  sick  was  quite 
variable.  After  doses  of  J  pound  to  two  pounds  the  animals  were  sick 
for  from  one  to  eighteen  hours,  averaging  about  five  or  six  hours.  As 
several  of  these  sheep  recovered  during  the  night,  we  do  not  know 
exactly  how  long  they  were  sick.  Most  of  the  sheep  which  died  from 
the  direct  effects  of  death  camas  poisoning  were  sick  from  twenty  to 
twenty-five  hours;  and  one  was  down  and  unable  to  rise  for  nearly 
three  days  before  it  died. 

Some  Typical  Cases  of  Death  Camas  Poisoning  in  Sheep. 

Case  1.  A  yearling  wether  weighing  81  pounds  was  fed  J  pound  of 
the  leaves  of  death  camas  at  11 : 10  a.  m.  May  5,  1918.  At  2 :  55  p.  m.  it 
began  to  froth  at  the  mouth  and  made  attempts  to  vomit.  The  breath- 
ing was  very  irregular,  alternately  rapid  and  slow.  At  4 :  30  p.  m.  the 
animal  seemed  to  be  getting  better  and  by  5  p.  m.  it  appeared  to  have 
recovered  completely. 

Case  2.  About  one  month  later,  on  June  4,  1918,  the  same  sheep,  now 
weighing  93  pounds,  was  fed  J  pound  at  2 :  35  p.  m.  At  3 :  50  p.  m.  it 
began  slobbering;  and  at  4:05  p.  m.  it  was  nauseated  and  began  to 
vomit.  The  breathing  was  at  first  fast'  and  shallow,  then  slow  and  full,, 
with  occasional  slight  pauses.  By  4 :  30  it  had  vomited  an  amount  esti- 
mated at  f  of  a  quart.  Vomiting  ceased  soon  afterward  and  by  4 : 50 
the  sheep  was  much  better.  When  next  observed,  at  7  :45  p.  m.,  it  was 
eating  hay  and  appeared  to  have  fully  recovered. 


16 


Case  3.  A  yearling  wether  weighing  56  pounds  was  fed  £  pound  of 
death  camas  leaves  at  3  : 15  p.  m.  May  22,  1918.  At  4 :  35  it  was  froth- 
ing at  the  mouth  and  trying  to 
vomit.  At  4 : 40  it  was  vomiting 
freely.  At  7  p.  m.  it  was  still 
frothing  at'  the  mouth,  but  had 
ceased  vomiting  and  was  getting 
better.  At  8  p.  m.  it  seemed  to 
have  recovered.  At  10  p.  m.  it  was 
again  slobbering  a  little.  Next 
morning  at  8  o'clock  it  had  fully 
recovered. 

Case  4.  A  yearling  wether  fed  f 
pound  of  the  leaves  at  9 : 25  a.  m. 
May  24,  1918,  began  slobbering  a 
little  at  2 : 15  p.  m.  This  gradu- 
ally increased,  and  at  3 : 20  it  was 
foaming  freely  at  the  mouth.  At 
4  p.  m.  it  was  still  slobbering  a 
little ;  but  at  4 : 15  it  began  eating 
grass  and  seemed  to  have  recovered 
fully.  No  other  sj^mptoms  were 
noted. 

Case  5.  A  ewe  weighing  75 
pounds  was  fed  1J  pounds  of  death 
camas  at  11:50  a.  m.  At  2:30 
this  sheep  was  grinding  its  teeth 
and  slobbering  freely.  At  3 :  40  it 
was  dull  and  stood  with  the  head 
and  ears  drooping,  still  frothing 
freely  at  the  mouth.  At  4 :  30  the 
animal  appeared  to  have  nearly 
recovered,  and  was  nibbling  at 
feed. 

Case  6.  A  ewe  weighing  68 
pounds  was  fed  1J  pounds  of  death 
camas  at  10:  40  a.  m.  May  9,  1918. 
It  began  to  froth  at  the  mouth  at 
1:20  p.  m.  At  about  1:30  it 
vomited  a  considerable  amount.  At 
2 : 30  it  was  slobbering  freely,  and 
Figure  8.  Death  Camas  Poisoning.  stood  with  drooping  head ;  showing 

a  decided  weakness  in  the  hind  legs.  At  3 :  30  it  was  salivating  less 
freely,  but  still  stood  with  head  drooping.  At  4 : 30  it  was  getting 
better ;  but  was  still  slobbering  a  little,  and  refused  to  eat.  At  6  :  40  it 
appeared  to  have  fully  recovered. 

Case  7.  A  ewe  weighing  83  pounds  was  fed  three  pounds  of  death 
camas  leaves  on  May  15,  1918,  at  10  a.  m.  At  1 :  30  p.  m.  it  was  slob- 
bering freely,  was  weak,  and  staggered  when  made  to  move.  The 
breathing  was  labored,  and  at  times  the  animal  vomited.  These  symp- 
toms continued,  the  animal  growing  worse  until  3  p.  m.  and  becoming 
weak  enough  by  4  p.  m.  to  stagger  when  walking ;  it  was  then  so  weak 


17 


that  it  could  easily  be  pushed  over.  The  mucous  membranes  of  the 
mouth  and  tongue  were  bluish.  At  7  :  30  p.  m.  it  seemed  better,  and  did 
not  appear  so  weak.  At  9  a.  m.  next  day  it  was  down  flat  on  the  side 
and  unable  to  rise.  At  11  a.  m.  it  had  twitching  movements  of  the 
muscles  similar  to  those  in  strychnine  poisoning.  The  animal  remained 
down  all  that  day.  Next  morning  it  was  still  down  and  appeared  to  be 
getting  weaker;  the  breathing  was  labored  and  was  accompanied  by 
peculiar  grunts.  At  9  a.  m.  on  the  18th  it  was  found  dead,  but  still 
warm. 

Case  8.  A  ewe  weighing  77  pounds  was  fed  three  pounds  of  death 
camas  at  11 :  20  a.  m.  May  22,  1918.  At  12 :  30  it  was  frothing  at  the 
mouth ;  by  1 : 30  it  was  frothing  freely  at  the  mouth  and  vomiting ; 
these  symptoms  continued  until  about  2  :  30.  By  2 :  50  the  animal  was 
weak  in  the  hind  legs  and  staggered  when  made  to  walk.  The  animal 
continued  to  get  worse,  and  by  4  p.  m.  was  very  weak  and  dull,  standing 
with  head  and  ears  drooping  and  the  back  arched.  At  4 :30  it  vomited 
again.  At  7  a.  m.  the  animal  was  very  dull,  and  staggered  when  made 
to  move.  It  continued  to  grow  worse  until  10  p.  m.  Next'  morning, 
at  8  a.  m.  it  was  very  weak  and  unable  to  get  up.  It  remained  in  this 
condition  all  the  forenoon ;  and  died  quietly  at  1 :  30  p.  m. 

Meadow  Death  Camas  (Zygadenus  venenosus)  Feeding  Experiments  with  Sheep. 
Only  three  feeding  tests  were  made,  as  the  plant  is  not  at  all  abun- 
dant on  the  ranges  in  western  Nevada ;  and  material  for  the  tests  was 
necessarily  limited.  It  is  much  less  important  on  Nevada  ranges  than 
the  foot-hill  death  camas.  The  results  of  the  three  feedings  are  sum- 
marized in  Table  II. 

TABLE  II 

MEADOW  DEATH  CAMAS  (Z.  venenosus}.    THE  GREEN  LEAVES  AND  FLOWERS 

FED  TO  SHEEP. 


Animal 
No. 

Weight 
Ibs. 

Date  fed 

Time  fed 

Amount 
fed,  Ibs. 

Time  symptoms 
appeared 

Time  of  death 
or  recovery 

Final  result 

37 

90 

6-  9-19 

9:45  a.  m. 

\ 

Negative 

37  
62 

93 

101 

6-11-19 
6-26-19 

10:50  a.  m. 
11:00  a.  m. 

1 
2 

1:40  p.  m. 
11:50  a.  m. 

5:00  p.  m. 
After  11:00  p.  m. 

Recovery 
Death 

The  experiments  summarized  in  Table  II  show  that  this  plant  is 
poisonous  and  that  amounts  of  one  pound  or  more  will  cause  serious 
poisoning  in  sheep.  The  symptoms  produced  by  this  plant  are  almost 
identical  with  those  described  for  the  foot-hill  species,  as  will  be  seen 
from  the  following  typical  cases : 

Typical  Cases  of  Poisoning  in  Sheep,  Meadow  Death  Camas. 

Case  1.  A  ewe  weighing  93  pounds  was  fed  one  pound  at  10 :  50  a.  m. 
At  1 :  40  p.  m.  it  was  foaming  at  the  mouth.  At  2 :  40  it  was  chewing 
cud,  but  still  foaming  at  the  mouth.  At  5  p.  m.  it  appeared  to  have 
recovered. 

Case  2.  On  June  26,  1919,  a  ewe  weighing  101  pounds  was  fed  two 
pounds  of  the  plant  at  11  a.  m.  At  11 :  50  it  was  foaming  at  the  mouth 
and  vomiting.  At  1  p.  m.  the  respiration  was  rapid  and  irregular, 
varying  from  55  to  70  per  minute.  It  still  frothed  freely  at  the  mouth, 
the  froth  being  scattered  all  over  the  pen.  By  4 : 15  it  was  very  weak, 
staggered  when  walking,  trying  to  vomit.  The  animal  then  appeared 


18 


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Species  of  plant 

Part  of  plant  fed 

Dose  

Number  fed  

Number  made  sick  
Number  of  deaths 

N  umber  showing  slobber 
Retching  and  regurgitat 
Respiration  rapid,  irregi 
Weak  and  dull... 

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15 
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Mouth  and  tongue  blue  . 
Twitching  of  muscles.. 

19 


to  be  strangling,  perhaps  due  to  froth  getting  into  the  windpipe.  It 
fell  at  4 :  30  and  could  not  get  up  again ;  at  4 : 45  it  got  up,  but  could 
barely  walk.  At  7  p.  m.  it  was  down  and  could  not  be  induced  to  rise. 
It  continued  to  get  weaker  and  duller  until  10 : 30  p.  m.,  when  the 
observer  left  for  the  night.  The  animal  probably  died  soon  afterward ; 
as  it  was  dead,  cold  and  stiff,  at  8  the  following  morning. 

A  Table  of  Symptoms  of  Death  Camas  Poisoning  in  Sheep. 

Table  III  gives  in  very  condensed  and  concrete  form  the  effects  of 
various  quantities  of  death  camas  (Z.  paniculatus  and  Z.  venenosus) 
when  fed  to  sheep  (see  page  18). 

Feeding  the  Green  Foot-Hill  Death  Camas  to  a  Ewe  with  Suckling  Lamb. 

Reports  from  various  sources  made  it  seem  possible  that  suckling 
lambs  might  be  poisoned  by  alkaloids  secreted  in  the  mother's  milk 
when  the  ewes  fed  upon  this  plant,  and  before  the  lambs  were  old 
enough  to  nibble  at  it.  To  test  this  matter,  a  ewe  with  a  suckling  lamb 
was  fed  the  foot-hill  death  camas  under  the  conditions  listed  in 
Table  IV. 

TABLE  IV 

FOOT-HILL  DEATH  CAMAS  (Z.  paniculatus).    THE  FRESH  LEAVES  FED  TO  A  EWE 

WITH  SUCKLING  LAMB. 


Animal 
No. 

Date 

Time  fed 

Amt. 
fed, 
Ibs. 

Weight 
Ibs. 

Time 
symptoms 
appeared 

Time  of 
recovery 

Effect  on 
ewe 

Effect  on 
lamb 

37 

4-  1-19 

1*30  p.  m. 

j 

98 

Negative 

Negative 

4-  2-19 

3:30  p.  m. 

N  egative 

Negative 

4-  3-19 

1  '30  p.  m. 

Negative 

Negative 

4-  4-19 

1:30  p.m. 

Negative 

Negative 

4-  9-19 

9:00  a.  m. 

Negative 

Negative 

4-10-19 

8:40  a.  m. 

Negative 

Negative 

4-11-19 

9:00  a.  m. 

Negative 

Negative 

4-16-19 

8:40  a.  m. 

Negative 

.Negative 

4-17-19 

8:30  a.  m. 

11:30  a.  m. 

4:00  p.  m. 

Recovery 

Negative 

4-18-19 

9-30  a.  m. 

1 

10-00  a  m. 

11-00  a  m 

Negative 

4-19-19 

9:00  a.  m. 

j 

i 

7:30  p.  m. 

4-20—8:00  a.  m. 

Recovery 

Negative 

4-22-19 

10:00  a.  m. 

i 

. 

1:00  p.  m. 

2"00p  m 

Recovery 

Negative 

The  tests  recorded  in  Table  IV  show  that  although  the  ewe  was  fed 
amounts  varying  from  -J  pound  to  1£  pounds  and  was  made  sick  four 
times,  still  the  suckling  lamb  was  not  affected  during  any  of  the  twelve 
feedings  of  its  mother. 

In  the  case  of  the  ewe  these  feedings  would  also  seem  to  indicate  that 
there  is  little  or  no  tendency  for  a  sheep  to  become  immune  to  the 
poisonous  effects  of  death  camas  after  feeding  repeatedly  upon  it. 

Feeding  Green  Foot-Hill  Death  Camas  to  Cattle. 

Table  V  summarizes  the  results  of  eighteen  tests  in  which  the  fresh 
green  plants  were  fed  to  cattle  (see  next  page). 

It  appears  from  this  table  that  cattle  are  quite  susceptible  to  the 
poisonous  principle  of  the  foot-hill  death  camas.  Out  of  the  eighteen 
feedings,  ten  made  the  animal  sick;  but  no  deaths  occurred.  It  was 
almost  impossible  to  get  cattle  to  eat  more  than  two  pounds  of  the 
plant;  because  they  soon  became  so  violently  sick  that  they  vomited 
up  all  the  material  eaten.  Two  small  feedings  of  £  pound  each  had  no 
apparent  effect  upon  the  animals  fed;  but  quantities  of  from  f  of  a 
pound  to  two  pounds  usually  caused  symptoms  of  poisoning.  In  some 
instances  poisoning  was  quite  severe,  reducing  for  several  days  the 
vigor  and  strength  of  the  animal. 


20 


TABLE  V 
FOOT-HILL  DEATH  CAM  AS  (Z.  paniculatus) .     THE  GREEN  LEAVES  FED  TO  CATTLE. 


AnimaJ 
No. 

Weight 
Ibs. 

Date  fed 

Time  fed 

Amount 
fed,  Ibs. 

Time  symptoms 
appeared 

Time  of  death 
or  recovery 

Final  result 

137 

4-  8-19 

8:00  a.  m. 

i 

Negative 

203 

4-12-19 

8:45  a.  m. 

£ 

137 

4-10-19 

8:30  a.  m. 

I 

Negative 

165 

-10-19 

9-00  a  m 

I 

11-30  a  m 

165 

-15-19 

9:00  a.  m. 

| 

11-00  a  m 

165 

-  8-19 

8-30  a.  m. 

9'30  a  m 

4'30  p  m 

Kecovery 

203 

-10-19 

9:45  a.  m. 

137 

-12-19 

8:30  a.  m. 

Negative 

143 

-16-19 

9:00  a.  m. 

150 

4-25-19 

10:50  a.  m. 

About  12-00  m 

4-26  —  8'00  a  m 

egative 

208 

4-10-19 

10:20  a.  m. 

208 

4-16-19 

10:20  a.  m. 

10-50  a  m 

208 

4-  8-19 

9-00  a  m 

1 

tvecovery 

208 

4-12-19 

10-00  a  m 

1 

11  -30  a  m 

4  13  •  4  '00  p  m 

193 

4-16-19 

11-30  a  m 

1 

8-- 

220 

4-14-19 

10:20  a.  m. 

1* 

recovery 

5  

208 

4-19-19 

10-00  a  m 

if 

10-20  a  m 

4-22  —  8-00  a  m 

-        gative 

6 

193 

4-25-19 

9'30  a  m 

2 

lO'OO  a  m 

4~28    8  -00  a  m 

recovery 

Symptoms  Exhibited  by  Poisoned  Cattle. 

Slobbering  was  not  so  common  a  symptom  in  cattle  as  in  sheep,  while 
vomiting  was  much  more  common  and  more  profuse.  This  vomiting 
made  the  animals  appear  very  thin  until  they  recovered  sufficiently  to 
eat.  A  rise  in  the  rate  of  respiration  was  a  common  symptom. 
Severely  poisoned  cattle  became  very  weak  and  dull;  the  gait  was 
unsteady,  particularly  in  the  hind-legs,  the  animals  sometimes  stum- 
bling with  the  hind  feet.  A  few  were  either  so  weak  that  they  were 
unable  to  get  up,  or  else  they  would  fall  over  when  walking.  Grinding 
of  the  teeth  and  diarrhea  were  each  observed  in  a  single  animal. 

Length  of  Time  Required  for  Symptoms  to  Appear  in  Cattle. 

The  time  from  the  middle  of  the  feeding  period  until  cattle  became 
sick  varied  from  20  minutes  to  2^  hours,  averaging  about  1  hour  and 
7  minutes.  They  remained  sick  for  from  3  to  22  hours,  averaging 
hours. 


Some  Typical  Cases  of  Death  Camas  Poisoning  in  Cattle. 

Case  1.  A  calf  weighing  165  pounds  was  fed  f  of  a  pound  of  death 
camas  leaves  at  9  a.  m.,  April  10,  1919.  At  li  :  30  it  was  sick  and 
vomited  freely.  It  remained  sick,  vomiting  frequently,  until  1  :  30.  At 
3  p.  m.  it  appeared  to  have  recovered. 

Case  2.  A  calf  weighing  150  pounds  was  fed  J  pound  of  the  leaves 
at  10  :  50  a.  m.,  April  23,  1919.  It  vomited  between  noon  and  1  p.  m. 
At  3  p.  m.  it  was  lying  down  and  appeared  dull.  When  made  to  get  up 
it  walked  with  an  unsteady  gait.  At  5  p.  m.  it  was  up  and  eating  hay. 
At  8  a.  m.  next  day  it  was  still  slobbering;  but  by  5  p.  m.  it  had 
apparently  recovered. 

Case  3.  A  calf  weighing  208  pounds  was  fed  one  pound  of  death 
camas  at  9  a.  m.,  April  8,  1919.  At  10  a.  m.  it  began  vomiting  and 
frothing  slightly  at  the  mouth.  At  11  :  20  it  was  breathing  at  the  rate 
of  94  times  per  minute.  At  2  :  45  it  had  stopped  vomiting  and  the 
respiration  had  fallen  to  34  per  minute.  The  animal  was  still  slightly 
sick  at  3  :  30  p.  m.  but  was  eating,  and  appeared  to  have  nearly 


21 


recovered  at  4 :  30  p.  m.     At  8 :  30  next  morning  it  was  walking  with 
a  peculiar  gait,  frequently  stumbling  with  the  hind  feet. 

Case  4.  A  calf  weighing  208  pounds  was  fed  1J  pounds  at  10  a.  m., 
April  19,  1919.  At  10 :  20  a.  m.  it  began  vomiting,  and  vomited  again 
at  11 :  20  a.  m.  Was  grinding  the  teeth  almost  constantly  from  10 :  30 
until  noon.  At  noon  the  respiration  was  40  per  minute.  This  calf  was 
able  to  get  up  at  2  p.  m.,  but  walked  with  a  very  unsteady  gait,  espe- 
cially noticeable  in  the  hind  legs.  This  condition  continued  until  9 :  30 
p.  m.  At  8  o'clock  next  morning  it  was  still  weak  and  looked  very  thin. 


Figure  9.  Death  Camas  Poisoning. 
This  calf  shows  slobbering  after 
eating  death  camas.  This  symptom 
is  more  common  in  sheep  than  in 
cattle. 


Figure  10.  Death  Camas  Poisoning. 
This  calf  shows  a  common  symp- 
tom— weakness  in  the  hind-legs. 


It  ate  a  little  hay,  but  soon  quit ;  the  bowels  were  quite  loose.  At 
8  a.  m.  on  April  22,  it  appeared  to  have  recovered ;  but  was  still  thin 
and  a  little  dull. 

Case  5.  A  calf  weighing  193  pounds  was  fed  two  pounds  of  death 
camas  leaves  at  9 :  30  a.  m.  At  10  a.  m.  it  began  to  slobber,  the  respira- 
tion then  being  56  per  minute.  It  vomited  between  noon  and  1  p.  m. 
At  3  p.  m.  it  was  still  dull,  and  walked  with  an  unsteady  gait  when 
made  to  get  up.  Next  morning  it  appeared  to  have  fully  recovered. 

Meadow  Death  Camas,  Feeding  Tests  with  Cattle. 

Owing  to  the  scarcity  of  material,  few  tests  were  made  with  this 
species.  The  five  feedings  made  are  summarized  in  Table  VI. 

TABLE  VI 
MEADOW  DEATH  CAMAS  (Z.  vcnenosus).     THE  GREEN  LEAVES  FED  TO  CATTLE. 


Animal 
No. 

Weight 
Ibs. 

Date  fed 

Time  fed 

Amount 
fed.  Ibs. 

Time  symptoms 
appeared 

Time  of  death 
or  recovery 

Final  result 

8  

220 

6-11-19 

2:00  p.  m. 

Negative 

9  

235 

6-11-19 

2*30  p.  m. 

i 

Negative 

1  

10 

138 
330 

6-11-19 
6-11-19 

11:45  a.  m. 
2'40  p  m 

1 

12:45  p.  m. 

2:40  p.m. 

Recovery 
Negative 

8  

220 

6-12-19 

8:45  a.  m. 

i* 

1:00  p.m. 

6-13—8:00  a.  m. 

Recovery 

22 


Summary  of  Results  of  Feeding  Death  Camas  to  Cattle. 

Table  VII  shows  graphically  the  effect  of  various  amounts  of  death 
camas  when  fed  to  cattle  in  experimental  tests. 

TABLE  VII 

DEATH  CAMAS  (Z.  paniculatus  and  Z.  venenosus).     SUMMARY  OF  SYMPTOMS, 
FEEDING  EXPERIMENTS  WITH  CATTLE. 


Species  fed 

Zygadenus  paniculatus 

Zy  gadenus  venenosus 

Dose 

2 

3 
2 

1 
2 

5 

2 

1 
2 
9 

2 

1 

1 
3 
3 

1 

11 
1 

u 

1 
1 

2 

1 
1 

1 

1 

I 

1 

1 

1 
1 

H 

i 

Number  fed 

Number  made  sick  

Number  showing: 
Slobbering 

Regurgitating    

2 

.... 

1 

1 
1 

1 

1 

1 

1 

Dull 

Unsteady  gait    

? 

2 

i 

Reluctant  to  rise 

? 

Respiration  rapid  

1 

1 
1 

Stumbling  on  hind  legs 

Unsteady  on  hind  legs 

? 

Fall,  and  hardly  able  to  get  up 

1 

Grinding  teeth 

1 

i 

i 

Weak            .    .  . 

1 

1     1 

Conditions  Under  Which  Death  Camas  Poisoning  Is  Most  Likely  to  Occur. 

As  has  been  stated,  death  camas  contains  a  bitter  substance  extremely 
distasteful  to  both  sheep  and  cattle.  Consequently  the  plant  is  eaten  by 
these  animals  only  under  stress  of  extreme  hunger  or  prolonged 
starvation. 

Most  of  the  cases  of  death  camas  poisoning  have  occurred  early  in 
the  spring.  This  is  a  time  of  year  when  all  palatable  vegetation  is 
scarce,  and  range  animals  are  often  poor  and  hungry,  depending  of 
course  upon  the  way  in  which  they  have  been  handled  during  the 
winter.  Under  these  conditions,  on  a  range  supporting  very  little 
palatable  vegetation,  hungry  animals  will  eat  almost  any  plant  in  order 
to  satisfy  their  hunger.  This  is  well  illustrated  by  a  loss  of  cattle  which 
took  place  in  Elko  County. 

A  herd  of  cattle  were  being  trailed  through  sagebrush  country  where 
the  grass  and  weeds  were  just  beginning  to  grow,  but  where  a  consid- 
erable number  of  death  camas  plants  had  already  made  their  appear- 
ance. The  cattle  were  thin  and  hungry,  and  at  every  opportunity  they 
bit  off  the  death  camas  plants.  A  rather  large  number  of  cattle  died 
as  a  result  of  this  drive.  Some  of  the  poisoned  animals  that  were  left 
behind  recovered ;  those  that  were  driven  hard  in  most  cases  died  on  the 
trail. 

In  regard  to  cattle,  then,  it  may  be  said  that  the  following  are  the 
range  conditions  under  which  death  camas  poisoning  is  most  likely  to 
occur:  (1)  When  hungry  stock  are  unloaded  from  the  cars  in  spring 
and  turned  out  on  a  depleted  range  where  death  camas  is  common,  and 
there  is  very  little  grass;  (2)  When  cattle  are  trailed  from  one  range 
to  another  in  the  spring  when  all  palatable  feed  is  scarce;  (3)  When 
hungry  animals  in  poor  condition  are  turned  out  to  rustle  for  them- 
selves in  the  early  spring  before  the  grass  is  up,  so  that  they  are  forced 
to  graze  any  and  all  plants  in  order  to  satisfy  their  hunger. 

When  sheep  are  grazing  openly  and  quietly  on  a  range,  they  show 
great  care  in  the  selection  of  the  forage  they  eat.  However,  when  they 
are  being  trailed  from  one  place  to  another,  they  have  no  chance  to 


23  

choose  what  they  will  eat,  with  the  result  that  they  eat  anything  that  is 
not  absolutely  repellant.  If  death  camas  is  common,  and  it  usually  is, 
they  eat  so  much  of  it  that  they  get  more  of  the  poison  than  they  can 
throw  off.  They  are  constantly  forced  to  move  along  on  the  trail  by 
dogs  and  herders,  and  death  naturally  follows. 


Figure  11.  Thin  and  Hungry  Cattle  on  Poor  Pasture.  Early  in  the 
spring  animals  in  this  condition  are  ravenous  for  green  feed.  They 
will  then  eat  death  camas  or  other  poisonous  plants  which  ordinarily 
they  would  not  touch. 


Figure  12.     Cattle  on  Good  Mountain  Pasture.    Well-fed  animals  on  good 
range  will  ordinarily  avoid  poisonous  plants  almost  wholly. 

It  should  always  be  remembered  that  when  a  sheep  is  hungry  it 
usually  eats  greedily  the  plant  on  which  it  is  feeding,  or  else  rushes 
to  another  plant  for  fear  some  other  sheep  will  get  there  before  it  does. 
But  when  sheep  are  grazing  openly  and  quietly,  they  nip  off  only  the 
tender  and  juicy  parts  of  the  plant,  the  leaves  and  young  stems,  and 
carefully  select  the  plants  on  which  they  feed. 


24  

How  to  Avoid  Death  Camas  Poisoning  in  Sheep  and  Cattle. 

Evidently  in  order  to  avoid  losses  on  a  range  where  death  camas  is 
common,  sheep  should  be  so  handled  that  they  are  never  bunched  up  nor 
extremely  hungry.  If  they  are  to  be  driven  from  one  range  to  another, 
it  is  best  to  allow  them  to  graze  for  an  hour  or  two  in  the  morning  just 
as  openly  and  quietly  as  possible  before  starting  to  move  them.  This 
will  allow  all  the  animals  to  fill  with  good  forage  and  they  will  then  use 
greater  care  in  the  selection  of  their  food  for  the  remainder  of  the  day. 
This  would  not  be  the  case  if  they  were  started  on  the  trail  immediately 
after  leaving  the  bed-ground. 


Figure  13.  Sheep  Grazing  at  Will  on  Sagebrush  Range.  When  allowed 
to  feed  quietly  in  scattered  formation,  sheep  will  ordinarily  wholly 
avoid  death  camas  and  many  other  poisonous  plants. 

Another  very  important  point  is  to  get  the  sheep  off  the  bed-ground 
just  as  early  in  the  morning  as  possible.  When  a  sheep  beds  down  at 
night  it  is  usually  full  and  contented.  By  morning  it  is  beginning  to 
get  rather  empty,  and  the  longer  it  is  kept'  on  the  bed-ground  the 
hungrier  it  becomes ;  it  is  then  far  more  apt  to  be  poisoned  when  it  gets 
out  on  the  range  where  the  death  camas  is  common. 

In  most  of  the  cases  of  death  camas  poisoning  thus  far  observed,  the 
animals  were  poisoned  during  the  forenoon.  This  is  due  to  the  fact  the 
attractiveness  of  the  plant  decreases  as  the  stomach  becomes  full.  Thus 
plants  which  may  seem  to  be  highly  palatable  and  to  be  relished  during 
the  morning  hours  are  often  not  touched  at  all  later  in  the  day.  This 
is  quite  true  of  the  death  camas.  It  is  grazed  chiefly  during  the  early 
morning  hours,  and  is  seldom  touched  by  an  animal  whose  stomach 
is  nearly  full.  Therefore  it  is  highly  important  that  the  sheep  should 
be  so  handled  during  the  early  morning  hours  that  they  will  have  the 
greatest  freedom  in  the  selection  of  their  range  forage;  if  possible, 
during  this  part  of  the  morning  they  should  be  grazed  on  range  free 
from  death  camas,  or  where  it  has  only  a  very  scattering  growth. 


25  

In  Nevada  the  prevailing  method  of  handling  sheep,  especially  in  the 
spring  of  the  year,  is  to  establish  a  main  camp  from  which  the  sheep 
are  grazed  daily  until  all  the  feed  in  the  immediate  vicinity  of  the 
camp  has  been  eaten  out  to  a  distance  of  two  or  three  miles  in  every 
direction.  This  requires  long  daily  drives  back  and  forth  in  order  to 
get  away  from  range  that  has  already  been  grazed.  Thus  the  sheep  trail 
over  the  same  ground  each  day,  until  all  the  forage  on  the  range  around 
the  bed-ground  has  been  completely  eaten  off. 

This  method  of  handling  can  only  result  in  all  the  plants  being  eaten, 
whether  poisonous  or  not ;  for  the  most  attractive  ones  are  first  grazed, 
and  when  these  are  gone  the  less  palatable  ones  are  left  to  be  eaten, 
including,  of  course,  the  death  camas. 

In  order  to  avoid  the  losses  which  result  from  such  improper  methods 
of  handling  sheep,  they  should  be  allowed  to  bed  down  wherever  they 
happen  to  be  when  night  comes.  They  will  then  always  be  on  fresh 
feed  in  the  morning.  The  variety  of  forage  from  which  to  choose  will 
be  much  greater;  and  the  probability  of  poisoning  will  be  far  less; 
providing,  of  course,  that  the  animals  are  gotten  off  the  bed-ground 
early  in  the  morning  and  are  allowed  to  spread  out  and  graze  openly 
and  quietly,  each  ewe  with  her  lamb.  Close-bunched  grazing,  running, 
trailing,  and  massing  should  be  avoided ;  not  only  to  reduce  losses  from 
poisonous  plants,  but  also  for  the  good  of  the  ewe  and  her  lamb,  and 
for  the  most  full  and  effective  use  of  the  range  forage. 

Remedies  for  Death  Camas  Poisoning. 

For  animals  poisoned  by  death  camas  there  is  known  at  present  no 
practical  remedy.  The  best  treatment  is  to  let  the  poisoned  animals 
entirely  alone,  disturbing  them  only  when  it  is  absolutely  necessary. 
After  an  animal  has  been  poisoned  it  is  very  much  weakened  and 
should  be  given  all  the  care  that  is  practicable  on  the  range.  If  it  can 
be  kept  on  good  feed  and  driven  just  as  little  as  possible  for  the  first 
two  or  three  days,  it  will  often  recover  rapidly. 


SECTION    II 

The  material  included  in  this  section  is  of  greater  interest  to  chemists 
and  veterinarians  than  to  livestock  owners. 


29 


POST-MOETEM  CONDITIONS 

Autopsies  upon  six  sheep  whose  death  was  caused  by  death  camas  in 
feeding  experiments  showed  the  following  post-mortem  conditions : 

There  appeared  to  be  no  outstanding  lesions  which  would  serve  to 
indicate  a  characteristic  effect  due  to  poisoning  by  this  plant.  On  the 
whole,  the  lesions  shown  were  those  of  a  general  toxemia.  The  condi- 
tions were  such  as  are  found  more  or  less  uniformly,  with  individual 
variations,  after  death  caused  by  the  ingestion  of  various  toxic  or  semi- 
toxic  plants. 

Various  degrees  of  congestion  in  the  gastro-intestinal  tract  and  in 
its  lymphatic  system  appeared  to  be  prominent  symptoms.  In  some 
instances  the  same  condition  was  also  found  in  the  kidney,  spleen,  and 
liver.  The  lungs  appeared  to  show  no  change.  In  some  cases  the  heart 
displayed  small  hemorrhages  beneath  the  epicardium  and  endocardium, 
characteristic  of  toxemia.  Considerable  quantities  of  free  fluid  were 
observed  in  the  thoracic  and  abdominal  cavities. 

THE  ACTIVE  PRINCIPLE  OF  DEATH  CAMAS 

It  has  long  been  known  that  alkaloids  are  partially,  if  not  wholty, 
responsible  for  the  poisonous  properties  of  the  death  camas.  Different 
investigators  have  studied  various  species  of  Zygadenus,  and  the  lack 
of  uniformity  in  the  results  obtained  is  not  surprising.  In  the  bulk  of 
the  work  reported  it  is  stated  that  alkaloids  have  either  been  isolated 
or  detected;  a  single  worker  found  resins  in  the  plant  which  had 
poisonous  properties.  Later  attempts  to  verify  these  findings  in  closely 
related  species  resulted  in  failure. 

Two  physiologically  active  resins  were,  found  by  Vejux-Tyrode  in 
1904  in  the  bulbs  of  Zygadenus  venenosus  from  Montana.  From  one  of 
the  resins  he  isolated  a  basic  body  which  he  designated  zygadinein  and 
an  acid — zygadenic  acid.  In  animal  experiments  he  found  the  zyga- 
dinein to  be  the  active  principle.  When  given  in  minute  doses  to 
guinea  pigs,  rabbits,  and  dogs  it  produced  salivation,  staggering  and 
respiratory  paralysis  followed  by  death,  in  some  cases  in  a  few  minutes 
but  usually  within  a  few  hours.  In  1913  the  chemists  of  the  Wyoming 
Station,  F.  W.  Heyl  and  F.  E.  Hepner,  investigated  Zygadenus  inter- 
medius  for  similar  toxic  resins,  but  were  unable  to  isolate  any  toxic 
substance  from  the  resin  or  even  to  establish  the  toxicity  of  the  resin 
itself. 

The  work  of  early  investigators  consisted  of  color  tests  made  upon 
impure  products  and  led  to  conclusions  that  the  alkaloids  in  the  species 
tested  belonged  to  the  veratrine  group. 

In  1903  George  Heyl  obtained  an  alkaloid  from  a  California  species 
of  Zygadenus.  The  alkaloid  found  amounted  to  0.4%.  It  was  soluble 
in  ether  and  nearly  insoluble  in  water.  Its  melting  point  was  134—135°. 
It  formed  a  crystalline  hydrochlorid. 

Alkalodial  analyses  of  Zygadenus  intermedius  were  made  in  Wyo- 
ming in  an  endeavor  to  determine  the  quantity  of  alkaloidal  material 
present  in  the  different  parts  of  the  plant.  On  account  of  the  lack  of 
suitable  methods  for  the  determination,  the  results  are  probably  not  so 


30  

accurate  as  might  be  desired  and  show  only  a  fair  degree  of  uniformity. 
Figures  for  the  amounts  found  in  the  dried  leaf  varied  from  0.57% 
to  0.66%;  bulb,  0.188%  to  0.57%;  flower,  1.07%  to  1.35%;  root, 
0.306%  to  0.32%. 

A  quantity  of  material  was  prepared  and  submitted  to  Dr.  Phillip 
Mitchell  and  Mr.  Geo.  Smith  for  toxicological  experiments.  The  mate- 
rial used  in  these  experiments  was  not  the  more  highly  purified  crystal- 
lized alkaloid  which  was  reported  on  later.  It  was  found  that  when 
injected  intraperitoneally  a  quantity  between  4.6  mg.  and  5.1  mg.  would 
produce  death  in  a  guinea  pig.  When  administered  by  mouth  a  com- 
paratively large  quantity  was  required  for  fatal  effects  in  the  guinea 
pig.  The  larger  amount  necessary  was  partially  accounted  for  by 
the  fact  that'  the  material  caused  vomiting.  In  the  guinea  pig  the 
effects  of  the  material  appeared  to  be  the  same  after  subcutaneous  or 
intraperitoneal  injection  or  after  feeding. 

The  mixed  alkaloids  cause  vaso-dilatation  and  apparently  affect  the 
cardio-inhibitory  center,  slowing  the  heart  action.  Respiration  was 
slowed.  After  doses  approaching  the  fatal  quantity  the  heart-beat 
becomes  rapid  and  irregular  and  there  is  convulsive  respiration.  In 
dogs  the  fatal  dose  given  intravenously  stopped  the  heart  before 
respiration  ceased.  When  either  injected  or  fed,  it  had  a  powerful 
action  both  as  a  purgative  and  an  emetic. 

Later,  in  the  Wyoming  experiments,  a  more  highly  purified  alkaloid 
was  obtained  which  could  be  crystallized  from  alcohol  and  benzene. 
The  crystalline  material  from  benzene  melted  at  200-210°  and  was 
found  to  have  the  formula  C39H63N010.  The  physiological  action  was 
tested  by  Dr.  Phillip  Mitchell,  who  reported  its  effects  to  be  different 
from  those  found  for  the  mixed  alkaloids.  Its  behavior  was  in  general 
much  like  the  alkaloid  veratrine  and  it  required  comparatively  large 
quantities  to  kill  guinea  pigs.  Unlike  the  mixed  alkaloids  it  had  no 
noteworthy  effect  on  the  heart  and  apparently  caused  complete  loss 
of  muscular  control. 

In  1918  Dr.  C.  A.  Jacobson  of  the  Nevada  Station  reported  obtaining 
a  new  alkaloidal  product  from  Zygadenus  paniculatus.  This  alkaloidal 
product  was  designated  by  him  as  "Z-alkaloid."  The  crude  alkaloid  was 
prepared  by  extracting  the  ground  and  dried  plant  with  95%  alcohol, 
concentrating  the  extract  to  a  sirup  and  pouring  into  a  dilute  solution 
of  tartaric  acid  to  remove  resins  and  other  impurities.  The  clear  acid 
solution  was  further  purified  by  extraction  with  ether ;  and  the  crude 
alkaloid  was  precipitated  by  the  addition  of  sodium  carbonate.  The 
precipitate  was  an  amorphous  sticky  mass  poisonous  to  rabbits.  The 
liquid  containing  the  precipitated  solid  matter  was  extracted  with 
ether.  It  was  found  that  if  the  ether  was  completely  removed  on  the 
water  bath,  the  material  would  then  undergo  violent  effervescence  and 
the  resulting  product  would  no  longer  be  poisonous.  If,  however,  the 
last  of  the  ether  was  allowed  to  evaporate  in  the  air  at  ordinary  tem- 
peratures no  effervescence  took  place  and  the  resulting  material 
retained  its  potency.  Further  purification  was  effected  by  re-solution 
in  tartaric  acid,  removal  of  impurities  with  ether,  neutralization  and 
extraction  with  ether  and  chloroform. 

The  more  purified  Z-alkaloid  had  an  increased  toxicity,  about  0.35 
gram  being  found  to  be  lethal  for  rabbits  when  administered  by  mouth. 


• 31  

The  Z-alkaloid,  which  constituted  about  0.3%  of  the  dried  plant,  was 
soluble  in  ethyl  and  methyl  alcohol,  chloroform,  acetone,  and  less  so  in 
benzene  and  carbon  tetrachlorid.  On  standing  several  months,  it 
resinified  to  a  white  substance  without  change  in  its  toxicity  or  solu- 
bility. On  long  standing,  an  alcohol-insoluble  crystalline  material 
separated  to  the  extent  of  about  1%  of  the  original  mass,  but  on  account 
of  the  small  quantity  obtained  its  physiological  action  could  not  be 
determined.  Various  compounds  of  the  Z-alkaloid  were  prepared ;  and 
from  the  data  obtained  it  appeared  that  it  is  not  the  same  as  the  com- 
pound named  Zygadinein  which  was  obtained  at  the  Wyoming  station. 


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